April 2, 2007 -- Skin cancer due to sun exposure appears faster -- and is
more severe -- in males than in females, mouse studies show.

It's well known that men are more likely to get skin cancer than women are.
Men get twice the overall number of skin cancers and three times more squamous
cell carcinomas than women do, notes Tatiana M. Oberyszyn, PhD, assistant
professor of pathology at Ohio State University in Columbus.

Why? Researchers usually say this is because men are more likely than women
to have outdoor jobs -- and that they are less likely to protect their skin
with sunscreen, shirts, and hats. Oberyszyn wondered whether this is true.

To test the theory, Oberyszyn's team exposed a breed of hairless mice to
ultraviolet rays from a sun lamp. The mice underwent eight- to 10-minute
tanning sessions three times a week for six months. That was enough to give
both male and female mice skin cancer.

"We found males got skin tumors earlier, got more of them, and more of
the tumors were severe," Oberyszyn tells WebMD.

Men's Skin More Sensitive?

What was going on? Tests of male and female mouse skin turned up a
surprising finding. The male skin cells carried fewer antioxidants than the
female skin cells.

"Our skin is exposed to both physical and environmental stimuli all the
time," Oberyszyn says. "Our immune system keeps us healthy. But the
immune system can overreact sometimes. You get overproduction of reactive
oxygen species -- and antioxidants protect against this."

The researchers are now looking at human skin to see if men really are like
mice.

"We think male skin is just more sensitive," Oberyszyn says.
"Perhaps men need something that would provide with them more antioxidants
-- maybe diet, maybe a skin cream. In addition to sunscreen, maybe men need to
pay more attention to their skin than women do. It is not a cosmetic thing; it
really is a health issue."

Marianne Berwick, PhD, is the head of cancer epidemiology and prevention
at the University of New Mexico in Albuquerque. Berwick agrees with
Oberyszyn that there's a huge difference between men's skin and women's
skin.

However, she notes that men really do get more exposure to cancer-promoting
ultraviolet light than women do.

"This current study is solid, good research, but it is not the whole
story," Berwick says. "I would hate to see people taking more
antioxidants or putting it on their skin because of this. The differences
between male and female skin are due to intrinsic biology and are not simply a
matter of antioxidants themselves."